人工中点在不对称三相三线制正弦电路功率测量中的应用研究

Study on the Application of Artificial Midpoint in Power Measurement of Asymmetric Three-phase Three-wire Sinusoidal Circuit

三相电路中总有功功率的测量是学术和工程的重要内容。三相三线制是三相电路的一种形式。人工中点在三相三线制电路功率测量中得到了广泛应用。首先介绍应用人工中点测量三相三线制正弦电路有功功率的基本原理,然后理论分析了人工中点测量电路的测量结果,最后通过计算实例验证理论分析的正确性。结果表明,对于电源和负载均不对称的三相电路,无论负载是星接还是三角接,应用了人工中点的测量电路均能够得到正确的测量结果,不会产生计量误差。

Measurement of the total active power in the three-phase circuit is an important part of scholarship and engineering.The three-phase three-wire system is a form of the three-phase circuit.Artificial mid-point is widely used for power measurement in the three-phase three-wire circuit.Firstly,the basic principle of measuring the active power of the three-phase three-wire sinusoidal circuit by applying artificial mid-point was introduced.Then,the result of circuit measurement through artificial mid-point was theoretically analyzed.Finally,correctness of the theoretical analysis was verified through calculation examples.The results indicated that correct measurement results with no measurement error could be obtained for a three-phase circuit with asymmetric power supply and asymmetric load,if an artificial mid-point measuring circuit was used,no matter whether the load had star or delta connection.